Telemetering system



Jan. 2l, 1947. B. M. CRAIG rs1-AL 2,414508 TELEMETERING SYSTEM Filed 0G12. 29, 1945 2 Sheets-Sheet l L @abi s] [72 E1' 517175175 B. M. CRAIG ETAL TELEMETERING SYSTEM 2 sheets-sheet 2 Filed OGC. 29, 1945 uf E i um m/ M Patented Jan. 21, 1947 UNITED STATES PATENT OFFICE TLMTERING SYSTEM Burnie M. Crai`g, Pasadena, and Grabriel M. Giannini, West Los` Angeles, Cali-f., assignors to Autoilight Corporation, South Norwalk, Conn., a corporation of Delaware Application October 29, 1945, Serial No. 625,366-

8 Claims. (Cl. 177-351) This invention relates to telemetering systems of the general type and kind in which a transmitting instrumentgenerates a succession of spaced electrical impulses of sign depending on direction of transmitter movement; and a receiver is actuated by those impulses to remotely operate mechanisms, controls, Vcounters or indicators, etc., in consonance with the operation of the transmitter. In such systems the transmitter may be manually operated, or may be actuated by any mechanism whose movement or whose condition may be desired to be reproduced or indicated at a distance. The operation is characterized by step-by-step energization and actuation of the receiver, and is further characterized by movement or actuation of the receiver in opposite directions according as the receiver receives positive or negative impulses.

A system of that general type and kind has been previously disclosed in the application of Gabriel M. Giannini, Ser. No. 597,459, filed June 4, 1945, and entitled Telemetric system. The present invention has the general objective and purpose of producing an instrumentation for the described type of telemetering systems, particularly adaptable to various industrial uses. The general nature of the invention will be best understood from the following description of preierred and illustrative forms of instruments which are shown in the accompanying drawings, in which Fig. 1 is a vertical central section, with parts in elevation, showing a preferred and illustrative form of transmitter element;

Fig. 2 is a section taken as indicated by line 2-2 on Fig. 1;

Fig. 3 is an enlargement of certain portions of Fig. 1;

Fig. 4 is a section taken as indicated by line 4-4 on Fig. 3;

Fig. 5 is a central vertical section, with parts in elevation, of a preferred and illustrative form of a receiver element;

Fig. 6 is a section on line 6-6 in Fig. 5;

Fig. rI is an enlarged detail cross section on line 'l--1 of Fig. 6; and l Fig. 8 is a fragmentary enlargement in certain parts of Fig. 6.

Referring first to Figs. 1 to 4 of the drawings, a suitable and preferably cylindric case is shown at 20, containing a, magnet system which is made up in cylindric assembly. The magnet system as shown comprises an axially located permanent magnet 2| with a pole-piece 22 at its upper end. The upper reduced cylindric portion of pole piece 22 extends spacedly through a circular axial opening 23 in an annular pole piece 24 which is mounted at its outer periphery on a cylindric circuit element 25. The lower end of magnetic circuit element 25 rests upon a lower circular yoke piece 26 upon which the lowerend of permanent magnet 2l also rests. rIfhe parts so far described areall composed of magnetically permeable material, preferably of low reluctance. A series of bolts or cap screws 2l (only one of which is shown in Fig. 1) pass through the lower yoke 26 and are threaded into an upper annular clamping member 2t, of non-magnetic material, acting to hold pole piece 22 in close contact with the upper end of permanent magnet 2| and to hold the lower end of the magnet in close contact with yoke 2B. And a series of screws 23 (only one of which is shown in Fig. 1) pass through lower yoke 26 and clamp 28 and are screw-threaded into upper annular pole piece member 24 to forcibly hold member 24, member 25 and yoke 23 in close contact. The assembled magnetic circuit thus has an annular air gap in the bore 23 of pole piece 24.

In the annular air gap at 23 a moving coil 35, wound as a helix on an axis which coincides with the central vertical axis of the magnetic system, is carried by va sleeve 36 which depends frein an elastically flexible diaphragm 31,. the sleeve `and diaphragm being of `non-magnetic material. The diaphragm is mounted at its outer periphery upon an upstanding flange 38 which is conveniently formed as an integral part of annular pole piece 24; an annular hold down ring 39 and screws 4U serving to rigidly secure the outer edge of the diaphragm. The diaphragm is preferably perforated with a pattern of spiral slots 4I. By such perforations the flexibility of the diaphragm may be controllably increased 'Without making the diaphragm too thin. Although other suitable spring means may be employed to maintain the coil in a normal medial position, and to return it to that position upon release from a Adisplaced position at either side of the medial position; preferably that spring means is embodied in the described elastic diaphragm constructed of suitable spring metal or other material, such for instance as phosphorbronze,` bre or plastic. Diaphragm 31 may be, and is preferably shown as flat in its annular portion between its outside edge and the depending sleeve 36. It is that portion of the diaphragm structure which is elastically flexible.

.Suitable damping means may be used for dampingfree oscillations of the coil,but in the structure as described no special damping means has been found necessary. The diaphragm is to some extent air damped, and may be made of a material which is not perfectly elastic. Also the sleeve 3S may be of a conductive material, to be damped by eddy currents. But in any case, Whether or not any such damping is applied to the coil movements, current generation in the coil by reason of its movement tends to retard that movement and thus to damp oscillation.

Within the diameter of depending sleeve 36 the diaphragm -is either formed' into a conical formation 56, preferably projecting upwardly, or that conical formation is rigidly secured to the diaphragm as by brazing, welding or cementing as shown in Figs. 3 and 4. The purpose of providing this formation is to provide a rigid and inflexible motion transmitting member carried by the elastically flexible diaphragm and joining the diaphragm at the circle which is dened by the coil carrying sleeve; so that movements imparted to the apex of the conical formation,

. or to a member carried by it, will be wholly transmitted to coil 35 carried on depending sleeve 35. The mechanism which is now about to be described is mechanism for imparting to the rigid cone 5i) a movement or force which will flex the diaphragm selectively in either direction and will release the diaphragm for free snap action back to its normal position.

For that purpose the simple form of mechanism shown in the drawings, and particularly in Figs. 3 and 4, is preferred. As there shown a button or stud 6l] with an annular groove 6| is rigidly mounted on the apex of cone 5l). A forked arm 62 straddles the grooved portion of the stud and is pivoted at 63 on a pivot supporting bracket 64 which (see Fig. 1) depends from a mounting plate 65 which is spacedly supported above ring 39 and diaphragm 31 by the studs 66. Pivot 63 also carries an upstanding ringer 61, preferably pointed at its upper end. In the normal medial position of diaphragm 31, arm 62 stands in a horizontal position and nger 61, which is rigidly connected to the arm, stands in a vertical position. The ringer formation at its upper end, preferably pointed, is also preferably symmetric about a vertical line through axis 63.

The toothed periphery 1D of a disk or wheel 1|, which is mounted on a vertical axis, is posi# tioned just above the upper end of linger 61. This peripheral portion has a series of teeth 12 which depend far enough to engage the upper end of finger 61 as the toothed wheel rotates in either one direction or the other. The relaf tive opposite movements of the peripheral portion of wheel 1l which overlies nger 61 are indicated by the double headed arrow in Fig. 4. Wheel 1| is here shown as mounted on the vertical axis shaft 15 which is journalled immediately above the wheel in mounting plate 65 and at its upper end in another mounting plate 16 which is spacedly supported above mounting plate 65 by supports such as shown at 11. A pinion 18 on axis shaft 15 meshes with a gear 19 on the actuating or driving shaft 8l) which is also conveniently journaled in mounting plate 65 and 16. vWhile it will be understood that toothed wheel 1| may be driven either directly from an initial driving shaft, or through any suitable gearing train, the arrangement shown here is a typical one for driving the toothed wheel at an angular velocity somewhat greater than that at which the initial driving shaft is driven.

2,414,508 ff f We may now suppose initial driving shaft to be rotated by any means, either manually or from some connected mechanism. If the system is used for remote manual control, shaft 80 may merely have a handle or dial connected with it. On the other hand if the system is used for the remote actuation of some mechanism or indimovement applied to actuating shaft 80, andA lmoves the teeth T2 successively in one direction or the other into contact with upstanding finger 61. If we suppose that the teeth are moving toward the right in Fig. 4, then a tooth is moved toward the right against the lfinger to such a position as shown. Further movement willthen throw nger 61 over toward the right, and throw arm 62 upwardly, about pivot 63. The upward movement of finger 62 will be transmitted to diaphragm 31 through stud 50 and the rigid cone 50, iiexing the diaphragm upwardly and moving sleeve 36 and coil 35 upwardly. As thelower edge of a tooth wipes over the upper edge of the deflected nger, the nger and arm 62 and diaphragm 31 are suddenly released. The diaphragm then snaps back to its normal medial position under itsown spring action. That returnmovement is relatively fast. The total mass of the diaphragm and the parts directly supported thereby is made to bear such a relation to the elastic characteristics of the diaphragm that the whole system will have a natural frequency in the lower audible frequencies. Due to the rapid return movement of the diaphragm, an electrical pulse of comparatively high voltage isy generated in coil 35, to be transmitted to the receiver by any suitable circuiting. (Preferably one side of coil 35 isgrounded so that a single wire circuit to the receiver may be used.) The damping reduces its oscillation about the normal position to a small or negligible amplitude, so that the pulses of alternating signgenerated in the coil immediately following the generation of the first pulseA are of small or negligible amplitude and duration.

The instrument is so designed, including its gearing ratio of connection with the initial actu ating mechanism, that the velocity of diaphragm displacement by the initial forced movement of finger 6lV is much slower than the snap action return of the diaphragm when released. The current pulse which is generated bythe initial forced displacement of the diaphragm is therefore of very low or negligible voltage.

Consequently, upon movement of toothed wheel 1l in one direction, say toward the right in Fig. 4, the instrument will generate a spaced series of electrical pulses, all owing in the same direction. On the other hand, when toothed wheel 1l is rotated in the opposite direction, so that the relative movement in Fig. 4 is toward the left, the linger 61 is periodically forced over toward the left, depressing arm 62 and diaphragm 31, and periodically releasing to allow the diaphragm to spring upwardly to its normal position.l And, on

each such actuation of the diaphragm, the fast upward movementof coil 35 generates a pulse flowing in the opposite direction. The instrument thus generates a spaced series of electrical pulses, whose sign is dependent upon the direc.- tion of movement which is applied to the instrument. The total number of those successive impulses, added algebraically, then becomes an indication of the instant position of the instrument and of the member or mechanism which operates it.

In the receiver shown inFigs. 5 to 8, the magnet system, the elastically flexible diaphragm and the coil carried thereby are all preferably the same as the corresponding parts in the transmitter. Mounting plate 65a and its supports 65a are also substantially the same as the correspond-` ing parts'in the transmitter. That duplication is not necessary, but preferable for standardization of manufacture; The duplicate parts in Figs.

'5, 6 and 7 are marked with the same numerals as in Figs. 1 to e. The only differences in structure and function between the transmitter and receiver are in those parts which, in these preferred designs, are located above the diaphragm and are operatively associated with the diaphragm to cause diaphragm and coil movements in the transmitter, and to be actuated by the coil and diaphragm in the receiver-that is, to cooperate diaphragm and coil movements with movements of a shaft.

In the receiver a simple two-way ratchet mechanism is provided, to be actuated by diaphragm movements in one direction or the other, depending upon the direction of diaphragm displacement, depending in turn upon the sign of the pulse owing through the coil.

As shown in preferred form in the drawings, a central vertical indicator shaft I is mounted at its lower end in a bearing lill set in the upper end of pole piece 22. The shaft, and all theparts carried by it, are preferably of non-magnetic material. (In fact, in both instruments it is preferred that all parts except those forming the magnetic circuit be of non-magnetic material.) The upper end of shaft lill) passes through the upper mounting plate 65a, and is journalled therein, and as here shown carries an indicator pointer |93 at its upper end. A dial |04 may be mounted on the upper face of mounting plate 65a. As here illustrated, the receiver is thus an indicating instrument; but it will be understood that shaft may actuate any desired device or mechanism.

A double-faced ratchet wheel |65 is xedly mounted on shaft I @El a short distance above diaphragm 3l. Ratchet wheel |05 has ratchet teeth |96 on its upper side facing in one directionand ratchet teeth lill on its under side facing in the oppoiste direction. The wheel is also notched or toothed at lili! on its periphery to be engaged by a spring detent Hl which may be conveniently secured on the under face of mounting plate 65a as illustrated in Fig. 5.

Diaphragm 3l carries a centrallyarranged mounting member Il adapted to carry the oppositely facing pawls H and H2. As here shown, this mounting member comprises a ring H3 or angular cross section, secured directly to diaphragm 31 around its central opening, and carrying the lower pawl or pawls H2. Secured to ring ||3 there is another member which, as here shown, consists of a ring lid with two upward extensions H5 which carry at their upper ends the horizontal inward projecting extensions IIB. .An upper pawl Ill is mounted upon the under side of an extension H6. While it is sufficient to have only one upper pawl and one lower pawl, another oppositely facing pair may be mounted on ring ||3 and on the other upper extension IIE. Fig. 6 indicates two upper pawls The composite mounting member HB which carries the pawls is, like the conical formation 5|) of Fig. l, a relatively rigid movement transmitting member which joins the flexible diaphragm at the circle dened by the coil carrying sleeve.

For purposes of simplicity in structure the pawls are preferably spring pawls. In effect, they are swinging pawls having effective swinging centers but stopped in their swinging movement toward the ratchet wheel at their normal tuistressed positions. In their normal positions, and with diaphragm 37 in its normal medial position, both the upper and lower pawls preferably clear their respective ratchet teeth by a short distance, as shown in Fig. 7. When the coil receives a pulse of one sign, say positive, it moves the diaphragm and the parts mounted thereon in one direction, say downwardly. Upon such downward movement, the `upper pawl or pawls immediately move downward into engagement with the upper ratchet teeth and then the free end of the pawl is swung relatively upwardly, and in Fig. 7 toward the right, to move the ratchet wheel in a corresponding direction through a distance corresponding to one tooth spacing. The register teeth |68 are preferably spaced the same as the ratchet teeth, so that upon each actuation the ratchet wheel moves one register tooth under detent H39 and at the end of the operation detent |99 is resting in the next notch between teeth to hold the ratchet wheel in the position to which it has been moved by the pawl action.

Upon cessation of the received electrical pulse, the elastic diaphragm immediately moves back to its medial position. It may pass through and somewhat beyond its medial position, but being damped it does not pass far enough beyond that medial position to carry the lower pawl or pawls l2 upwardly far enough to displace ratchet wheel |05 through a distance more than a small fraction of a complete step. Thus, although the ratchet wheel may be momentarily reversely displaced through a short distance, it is not displaced far enough to displace detent |9 from the notch in which it is at the time engaged. In this connection it may be noted that detent |99, in the form of a flat spring, has a slight elasticity in a direction peripherally of the ratchet wheel.

Upon receiving an electrical pulse of the opposite sign, say negative, the coil moves the diaphragm and its carried parts in the opposite direction, say upwardly. Upon such movement, the lower pawl or pawls H2 are engaged with the lower ratchet teeth |61, and move the ratchet wheel in a direction opposite to that previously described, through a distance equal to one tooth spacing.

From what has been said, it will now be understood that the total displacement in one direction of the ratchet wheel, and of any parts, devices or mechanisms actuated thereby, will depend upon the number of received pulses of one sign; while the total displacement of the parts in the opposite direction will depend upon the number of received pulses of the opposite sign. The instant position of the actuated parts, with relation to any selected zero position, will always correspond to the algebraic sum of the positive and negative pulses which have been received.

No claim is made in this application to the feature of the moving coil, in and of itself in a telemetering system; that being the subject matter of a co-pending application led by Gabriel M, Giannini and Joseph F. Manildi, Ser. No. 625,364, filed October 29, 1945.

We claim:

1. A telemetering instrument comprising a magnet system whose circuit includes an air gap, a movable coil in the air gap, a damped elastic member supporting the coil normally in a medial position and for displacement in either of two opposite directions and acting to return the coil from either displacement to its medial position, a toothed wheel rotatively mounted on an axis parallel with the line of displacement movement of the coil, and means whereby movements of the toothed wheel in its two opposite directions of rtation through a distance of one tooth spacing are selectively cooperated respectively with the opposite displacements cf the coil from its medial position.

2. A telemetering instrument comprising a magnet system whose circuit includes an annular air gap, an annular coil located in the air gap, a damped elastic diaphragm supported concentrically with, and in a plane normal to, the axis of the coil and air gap and supporting the coil in a medial position in which the diaphragm is unstressed, the coil being displaceable in either of two opposite directions along said axis in accompaniment with stressed displacement of the diaphragm in corresponding directions, a rotatable shaft mounted on an axis parallel to the axis of diaphragm displacement, and means whereby rotational movements of the shaft 'through a definite angle in each of its two opposite directions of rotation are selectively cooper- :ated respectively with the opposite displacements yof thediaphragm from its medial position.

Y3. An instrument as defined in claim 1 and in which the last mentioned means comprises a pivoted ringer adapted to be 'wiped over by the teeth as the toothed wheel moves in either of its two opposite directions of movement, an arm rigidly connected with the nger to swing therewith, and connection between the arm and the coil.

4. An instrument as deiined in claim 1, in which the toothed wheel has oppositely facing ratchet teeth on its opposite side faces, and in which the last mentioned means comprises a pair of ratchet engaging pawls each swingingly connected with the coil to move therewith, the two pawls being positioned at opposite sides of the wheel, facing in opposite directions peripherally of the wheel and normally lying at equal and opposite angles to the plane of the wheel.

5. An instrument as dened in claim 2, and in which the last mentioned means'comprises a pivoted arm whose length normally lies parallel to the plane of the diaphragm and having its swinging end connected with the center ofthe diaphragm, a pivoted finger rigidly connected with the arm, the length of the ringer normally extending in a direction parallel to the axis of the coil and of diaphragm displacement, a wheel k mounted to rotate on an axis parallel to the axis of diaphragm displacement, and peripherally spaced teeth extending from the wheel' and 8 adapted to wipe over the free end of the finger upon wheel rotation in either direction;

6. An instrument as defined in claim 2, and ,in which the last kmentioned means comprises a shaft journalled on an axis coincident with the axis of diaphragm displacement, a ratchet wheel mounted on said shaft in a plane spaced from the diaphragm, said wheel having a series of ratchet teeth on each of its opposite side faces with the two series of teeth facing in opposite peripheral directions, and a pair of swinging pawls carried by' the diaphragm one Vopposed to each face of the ratchet Wheel, the two pawls facing in opposite directions peripherally of the wheel and normally standing at equal and opposite angles to the plane of the wheel. y

7. A telemetering instrument, comprising a magnet system arranged symmetrically about a central longitudinal axis and having an annular air gap concentric with said axis, a circular elastic damped diaphragm stationarily peripherally mounted concentrically with respect to, and in a plane normal to, said axis, an annular coil carried by the diaphragm concentrically'with the axis and projecting from the plane of `the diaphragrn` to lie in the annular air gap, a 'rigid structure associated with the central part of the diaphragm within the circle defined by the annular coil, an arm pivotally mounted on a stationary pivot and normally positioned with its length parallel to the plane of the diaphragm, means connecting the free end or" the arm to the center of the rigid diaphragm structure, a finger rigidly associated with the arm and projecting from the pivot in .a direction parallel to said axis, a linger actuating wheel mounted to rotate on an axis parallel to the diaphragm axis in a posi tion where its periphery rotates over the free end of the finger, and spaced teeth projecting from the periphery oi" the wheel and adapted to wipe over the end of the iinger.

8. A telemetering instrument, comprising a y magnet system arranged symmetrically about a central longitudinal axis and having an annular air gap concentric with said axis, a circuiar elastic damped diaphragm staticnarily peripherally mounted concentrically with respect to, and in a plane normal to, said axis, an annular coil carried by the diaphragm concentrically with the axis and projecting from the plane of the diaphragm tc lie in the annular air gap, a rigid structure associated with the central part of the diaphragm within the circle dened by the annular coil, a

shaft journalled on an axis coincident withthc axis of the coil and diaphragm, a ratchet wheel mounted on the shaft in a plane spaced from the diaphragm, two oppositely facing series of peripherally spaced ratchet teeth on the opposite side faces of the wheel, a rigid annular pawl support-1 ing structure secured to the diaphragm at thei circle defined by the annular coil, and a pair of oppcsitely facing swinging pawls carried by said rigid structure, saidvpawls being respectively engageable with the opposite series of ratchet teethl upon displacement of the diaphragm in opposite directions from its normal plane.

BURNIE M. CRAIG.

GABRIEL M. GIANNINI. 

